the arrays sequential. Originally committed as revision 18841 to svn://svn.ffmpeg.org/ffmpeg/trunk
		
			
				
	
	
		
			126 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			126 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * MLP codec common header file
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|  * Copyright (c) 2007-2008 Ian Caulfield
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #ifndef AVCODEC_MLP_H
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| #define AVCODEC_MLP_H
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| 
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| #include <stdint.h>
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| 
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| #include "avcodec.h"
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| 
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| /** Last possible matrix channel for each codec */
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| #define MAX_MATRIX_CHANNEL_MLP      5
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| #define MAX_MATRIX_CHANNEL_TRUEHD   7
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| /** Maximum number of channels in a valid stream.
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|  *  MLP   : 5.1 + 2 noise channels -> 8 channels
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|  *  TrueHD: 7.1                    -> 8 channels
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|  */
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| #define MAX_CHANNELS                8
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| 
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| /** Maximum number of matrices used in decoding; most streams have one matrix
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|  *  per output channel, but some rematrix a channel (usually 0) more than once.
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|  */
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| #define MAX_MATRICES_MLP            6
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| #define MAX_MATRICES_TRUEHD         8
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| #define MAX_MATRICES                8
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| 
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| /** Maximum number of substreams that can be decoded.
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|  *  MLP's limit is 2. TrueHD supports at least up to 3.
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|  */
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| #define MAX_SUBSTREAMS      3
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| 
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| /** maximum sample frequency seen in files */
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| #define MAX_SAMPLERATE      192000
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| 
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| /** maximum number of audio samples within one access unit */
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| #define MAX_BLOCKSIZE       (40 * (MAX_SAMPLERATE / 48000))
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| /** next power of two greater than MAX_BLOCKSIZE */
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| #define MAX_BLOCKSIZE_POW2  (64 * (MAX_SAMPLERATE / 48000))
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| 
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| /** number of allowed filters */
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| #define NUM_FILTERS         2
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| 
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| /** The maximum number of taps in IIR and FIR filters. */
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| #define MAX_FIR_ORDER       8
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| #define MAX_IIR_ORDER       4
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| 
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| /** Code that signals end of a stream. */
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| #define END_OF_STREAM       0xd234d234
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| 
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| #define FIR 0
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| #define IIR 1
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| 
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| /** filter data */
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| typedef struct {
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|     uint8_t     order; ///< number of taps in filter
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|     uint8_t     shift; ///< Right shift to apply to output of filter.
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| 
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|     int32_t     state[MAX_FIR_ORDER];
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| } FilterParams;
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| 
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| /** sample data coding information */
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| typedef struct {
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|     FilterParams filter_params[NUM_FILTERS];
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|     int32_t     coeff[NUM_FILTERS][MAX_FIR_ORDER];
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| 
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|     int16_t     huff_offset;      ///< Offset to apply to residual values.
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|     int32_t     sign_huff_offset; ///< sign/rounding-corrected version of huff_offset
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|     uint8_t     codebook;         ///< Which VLC codebook to use to read residuals.
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|     uint8_t     huff_lsbs;        ///< Size of residual suffix not encoded using VLC.
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| } ChannelParams;
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| 
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| /** Tables defining the Huffman codes.
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|  *  There are three entropy coding methods used in MLP (four if you count
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|  *  "none" as a method). These use the same sequences for codes starting with
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|  *  00 or 01, but have different codes starting with 1.
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|  */
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| extern const uint8_t ff_mlp_huffman_tables[3][18][2];
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| 
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| /** MLP uses checksums that seem to be based on the standard CRC algorithm, but
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|  *  are not (in implementation terms, the table lookup and XOR are reversed).
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|  *  We can implement this behavior using a standard av_crc on all but the
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|  *  last element, then XOR that with the last element.
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|  */
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| uint8_t  ff_mlp_checksum8 (const uint8_t *buf, unsigned int buf_size);
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| uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size);
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| 
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| /** Calculate an 8-bit checksum over a restart header -- a non-multiple-of-8
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|  *  number of bits, starting two bits into the first byte of buf.
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|  */
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| uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size);
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| 
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| /** XOR together all the bytes of a buffer.
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|  *  Does this belong in dspcontext?
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|  */
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| uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size);
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| 
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| void ff_mlp_init_crc(void);
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| 
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| /** XOR four bytes into one. */
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| static inline uint8_t xor_32_to_8(uint32_t value)
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| {
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|     value ^= value >> 16;
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|     value ^= value >>  8;
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|     return value;
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| }
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| 
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| #endif /* AVCODEC_MLP_H */
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